Histology Atlas of the Developing Mouse Digestive System With Emphasis From Prenatal Day 7.5 Through Early Postnatal Development

Digestive system development is a complex process, requiring precise molecular signaling interactions to produce various complex organs arising from a single primordium (the primitive gut tube). Abnormal development of this system is common in humans, leading to birth defects like structural anomalies (e.g., atresias, fistulas, stenosis) and/or functional deficits (e.g., dysautonomia, ileus), all of which impair digestion and passage of ingesta, thereby reducing nutrient uptake. Mouse models of disease (engineered and spontaneous) have provided many insights into the mammalian molecular mechanisms that are essential for guiding normal global and regional anatomic formation of the digestive system. Moreover, an understanding of normal development is an essential resource for identifying and characterizing aberrant phenotypes and toxic effects in embryonic and juvenile mice. This microscopic atlas details key developmental milestones for the upper and lower digestive tracts (including associated glands except liver) in a common wild-type mouse stock. This atlas uses a range of high-resolution, well-annotated color images to follow the evolving digestive system anatomy from initial formation of the primitive gut tube in utero (at embryonic day 7.5) through the appearance of adult-like features at weaning (postnatal day 21 in modern mouse colonies), including comparisons with similar features in humans.